Closed-circuit thermostat.



PATENTED MAY 12, 1908.

G. H. BOWEN. CLOSED CIRCUIT THERMOSTAT.

APPLICATION FILED JUNE 20,1907.

1120622502? $73M my GEORGE H. BOWEN, OF BOSTON, MASSACHUSETTS.

. CLOSED-CIRCUIT THERMOSTAT.

Specification of Letters Patent.

Patented May 12, 1908.

Application filed June 20, 1907. Serial No. 379,895.

T 0 all whom it may concern:

Be it known that I, GEORGE H. BOWEN, a citizen of the United States, residing in Boston, in the county of Suffolk and State of Massachusetts, have invented an Improvement in Closed Circuit Thermostats, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings re resenting like parts.

his invention relates to a thermostatic circuit controller and has for its object to provide a simple, efficient and reliable device, which is protected from external influences, as will be described. For this purpose I employ an inclosing tube preferably of glass within which the operative parts of the circuit controller are located and preferably sealed against atmospheric influences and also protected from in ury by external forces or devices.

In the present instance, the invention is shown in a normally closed circuit controller provided with a movable member of fusible material, which is supported by the inclosing tube.

Figure 1 is an elevation of the thermostatic circuit controller embodying this inventiorn Fig. 2, a longitudinal section of the circuit controller shown in Fig. 1, and Fig. 3, an end elevation of the controller shown in Fig. 1.

Referring-to the drawings, a, b, represent fixed termlnals, which are connected by a fusible piece 0 constituting the movable member of the circuit controller. a

The movable member a may be composed of fusible solder which melts at a predetermined temperature.

The fixed terminals or members a, b, are secured to or form part of binding posts d, e, which are carried by ca s, blocks or pieces f,

g, which fit over the en s of a tube It, preferably of glass, and provided with a contracted or reduced portion 11, which forms a support for the movable member 0 and separates the said tube into two chambers into which extend the fixed terminals a, b, which are located on opposite sides of the'contracted por tion of the tube h.

The glass tube it may be protected from injury by a guard, herein shown as strips or pieces 70 secured to the caps or blocks f, g.

The binding posts d, 6 may be secured to the capsf, g, by nuts m.

Normally the circuit is closed from one binding post to another, by the fusible mem ber c as represented in Fig. 2, but when the temperature in the vicinity of the thermostat reaches a redetermined point, the member c fuses and opens the circuit between the members a, b.

It will benoticed that the fusible member rests upon the tube 71, so that, when the latter is heated, the heat is transmitted directly to the fusible member.

The tube h is preferably made of glass, so that the condition of the thermostatic circuit controller may be seen at a glance.

Claims.

The combination with a thermostatic circuit controller comprising fixed terminals substantially in line with but se arated from each other, and a movable mem er of fusible material intermediate of said fixed terminals and connected with the same, of a transparent tube having a contracted portion forming chambers into which the fixed terminals extend and through which contracted portion the fusible member is extended in contact therewith to support the fusible member, substantially as described.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

' GEORGE H. BOWEN.

Witnesses:

JAs. H. CH RCHILL, J. MURPHY. 

